Two medicines, side by side
Dofetilide vs sotalol
Dofetilide and sotalol are both labeled for atrial fibrillation. Drugs@FDA records approvals of dofetilide since 1999 and of sotalol since 1992. Pharmacies paid $0.203 per dofetilide 125 mcg capsule and $0.0707 per sotalol 80 mg tablet (NADAC, October 7, 2026); the strengths differ, so the two prices are not like for like. Sotalol's other strengths are brand-only: $2.32 per mL (Sotylize 5 mg/mL oral solution). How each works, in its label's words: Dofetilide, “The mechanism of action is blockade of the cardiac ion channel carrying the rapid component of the delayed rectifier potassium current, I Kr.”; Sotalol, “Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties.”
Check it at the source: the dofetilide FDA label on DailyMed (effective April 21, 2026); the sotalol FDA label on DailyMed (effective December 16, 2024).
Highlights of the dofetilide record
Dofetilide (Tikosyn) · label of April 21, 2026
To minimize the risk of induced arrhythmia, patients initiated or re-initiated on TIKOSYN should be placed for a minimum of 3 days in a facility that can provide calculations of creatinine clearance, continuous electrocardiographic monitoring, and cardiac resuscitation. For detailed instructions regarding dose selection, see DOSAGE AND ADMINISTRATION .
Used for
From the label: indicationsMaintenance of Normal Sinus Rhythm (Delay in AF/AFl Recurrence) TIKOSYN is indicated for the maintenance of normal sinus rhythm (delay in time to recurrence of atrial fibrillation/atrial flutter [AF/AFl]) in patients with atrial fibrillation/atrial flutter of greater than one week duration who have been converted to normal sinus rhythm. […]
On the market
- Earliest approval on file
- October 1, 1999
- Generic labelers
- 12 labelers
- Pharmacy cost
- $0.203 per capsule
Supply and safety
- Shortage
- No current entry
- Recalls
- 6
Highlights of the sotalol record
Sotalol (Betapace) · label of December 16, 2024
LIFE-THREATENING PROARRHYTHMIA To minimize the risk of drug-induced arrhythmia, initiate or reinitiate oral sotalol in a facility that can provide cardiac resuscitation and continuous electrocardiographic monitoring. Sotalol can cause life-threatening ventricular tachycardia associated with QT interval prolongation. If the QT interval prolongs to 500 msec or greater, reduce the dose, lengthen the dosing interval, or discontinue the drug.
Used for
From the label: indicationsBetapace/Betapace AF is an antiarrhythmic indicated for: the treatment of life-threatening ventricular arrhythmias ( 1.1 ) the maintenance of normal sinus rhythm in patients with atrial fibrillation or flutter (AFIB/AFL) ( 1.2 ) Limitations of Use Betapace has not been shown to enhance survival in patients with life threatening ventricular arrhythmias ( 1.1 ) Avoid use in patients with minimally symptomatic or […]
On the market
- Earliest approval on file
- October 30, 1992
- Generic labelers
- 18 labelers
- Pharmacy cost
- $0.0707 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 1
Source: FDA drug labels via openFDA (Dofetilide label of April 21, 2026, Sotalol label of December 16, 2024); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do dofetilide and sotalol differ on the record?
How each works, in its label's words: Dofetilide, “The mechanism of action is blockade of the cardiac ion channel carrying the rapid component of the delayed rectifier potassium current, I Kr.”; Sotalol, “Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties.”
Both are in FDA's class antiarrhythmics.
Half-life, in each label's words: Dofetilide, “The terminal half-life of dofetilide is approximately 10 hours; steady state plasma concentrations are attained within …”; Sotalol, “The mean elimination half-life of sotalol is 12 hours.”
Both labels carry a boxed warning; the records quote them.
Generics: dofetilide since 2016; sotalol since 2000 (Drugs@FDA).
| Dofetilide | Sotalol | |
|---|---|---|
| Labeled for | Atrial fibrillation | Atrial fibrillation |
| Pharmacologic class | Antiarrhythmic | Antiarrhythmic |
| How it works (label) | Mechanism of Action Dofetilide shows Vaughan Williams Class III antiarrhythmic activity. The mechanism of action is blockade of the cardiac ion channel carrying the rapid component of the delayed rectifier potassium current, I Kr. | Sotalol has both beta-adrenoreceptor blocking (Vaughan Williams Class II) and cardiac action potential duration prolongation (Vaughan Williams Class III) antiarrhythmic properties. |
| Half-life (label) | The terminal half-life of dofetilide is approximately 10 hours; steady state plasma concentrations are attained within 2–3 days, with an accumulation index of 1.5 to 2.0. | The mean elimination half-life of sotalol is 12 hours. |
| Earliest approval on file (Drugs@FDA) | October 1, 1999 | October 30, 1992 |
| First generic approved | June 6, 2016 | May 1, 2000 |
| Generic labelers (NDC) | 12 labelers | 18 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.203 per capsule (Dofetilide 125 mcg capsule) | $0.0707 per tablet (Sotalol 80 mg tablet) |
| 12-month price change | -6% | +0.9% |
| Boxed warning | Yes | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 6 | 1 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 10,448 | 16,549 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to dofetilide
- every medicine labeled for the same conditions